266 research outputs found
Ambient seismic noise tomography of the southern East Sea (Japan Sea) and the Korea Strait
Group velocity maps were derived for the southern
East Sea (Japan Sea) and the Korea Strait (Tsushima Strait) for
the 5–36 s period range, which is sensitive to shear wave velocities
of the crust and the uppermost mantle. Images produced in our
study enhance our understanding of the tectonic evolution of a
continental margin affected by subducting oceanic slabs and a colliding
continental plate. The seismic structure of the study area
has not been described well because seismic data for the region are
scarce. In this study, we applied the ambient noise tomography
technique that does not rely on earthquake data. We calculated
ambient noise cross-correlations recorded at station pairs of dense
seismic networks located in the regions surrounding the study
area, such as the southern Korean Peninsula and southwestern
part of the Japanese Islands. We then measured the group velocity
dispersion curves of the fundamental mode Rayleigh waves from
cross-correlograms and constructed 2-D group velocity maps
reflecting group velocity structure from the upper crust to uppermost
mantle. The results show that three distinct anomalies with
different characteristics exist. Anomalies are located under the
Ulleung Basin (UB), the boundary of the Basin, and the area
between Tsushima Island and the UB. 1-D velocity models were
obtained by inversion of dispersion curves that represent vertical
variations of shear wave velocity at locations of three different
anomalies. The 1-D velocity models and 2-D group velocity maps
of lateral variations in shear wave group velocities show that the
high velocity anomaly beneath the UB originates from crustal
thinning and mantle uplift. Confirming the exact causes of two low
velocity anomalies observed under the UB boundary and between
Tsushima Island and the UB is difficult because additional information
is unavailable. However, complex fault systems, small
basins formed by faulting, and deep mantle flow can be possible
causes of the existence of low velocity anomalies in the region.This work was funded
by the Korean Meteorological Administration and Development Program
under Grant CATER 2012-5051
Cartilage regeneration using human umbilical cord blood derived mesenchymal stem cells: A systematic review and meta-analysis
Background and Objectives: Human umbilical-cord-blood-derived mesenchymal stem cells (hUCB-MSCs) have recently been used in clinical cartilage regeneration procedures with the expectation of improved regeneration capacity. However, the number of studies using hUCB-MSCs is still insufficient, and long-term follow-up results after use are insufficient, indicating the need for additional data and research. We have attempted to prove the efficacy and safety of hUCB-MSC treatment in a comprehensive analysis by including all subjects with knee articular cartilage defect or osteoarthritis who have undergone cartilage repair surgery using hUCB-MSCs. We conducted a meta-analysis and demonstrated efficacy and safety based on a systematic review.
Materials and Methods: This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. For this study, we searched the PubMed, Embase, Web of Science, Scopus, and Cochrane Library literature databases up to June 2022. A total of seven studies were included, and quality assessment was performed for each included study using the Newcastle–Ottawa Quality Assessment Scale. Statistical analysis was performed on the extracted pooled clinical outcome data, and subgroup analyses were completed. Results: A total of 570 patients were included in the analysis. In pooled analysis, the final follow-up International Knee Documentation Committee (IKDC) score showed a significant increase (mean difference (MD), −32.82; 95% confidence interval (CI), −38.32 to −27.32; p < 0.00001) with significant heterogeneity (I2 = 93%, p < 0.00001) compared to the preoperative score. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores at final follow-up were significantly decreased (MD, 30.73; 95% CI, 24.10–37.36; p < 0.00001) compared to the preoperative scores, with significant heterogeneity (I2 = 95%, p < 0.00001). The visual analog scale (VAS) score at final follow-up was significantly decreased (MD, 4.81; 95% CI, 3.17–6.46; p < 0.00001) compared to the preoperative score, with significant heterogeneity (I2 = 98%, p < 0.00001). Two studies evaluated the modified Magnetic Resonance Observation of Cartilage Repair Tissue (M-MOCART) score and confirmed sufficient improvement. In a study analyzing a group treated with bone marrow aspiration concentrate (BMAC), there was no significant difference in clinical outcome or M-MOCART score, and the post-treatment International Cartilage Repair Society (ICRS) grade increased.
Conclusion: This analysis demonstrated the safety, efficacy, and quality of repaired cartilage following hUCB-MSC therapy. However, there was no clear difference in the comparison with BMAC. In the future, comparative studies with other stem cell therapies or cartilage repair procedures should be published to support the superior effect of hUCB-MSC therapy to improve treatment of cartilage defect or osteoarthritis
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Controlling the Magnetic Anisotropy of the van der Waals Ferromagnet Fe3GeTe2 through Hole Doping.
Identifying material parameters affecting properties of ferromagnets is key to optimized materials that are better suited for spintronics. Magnetic anisotropy is of particular importance in van der Waals magnets, since it not only influences magnetic and spin transport properties, but also is essential to stabilizing magnetic order in the two-dimensional limit. Here, we report that hole doping effectively modulates the magnetic anisotropy of a van der Waals ferromagnet and explore the physical origin of this effect. Fe3-xGeTe2 nanoflakes show a significant suppression of the magnetic anisotropy with hole doping. Electronic structure measurements and calculations reveal that the chemical potential shift associated with hole doping is responsible for the reduced magnetic anisotropy by decreasing the energy gain from the spin-orbit induced band splitting. Our findings provide an understanding of the intricate connection between electronic structures and magnetic properties in two-dimensional magnets and propose a method to engineer magnetic properties through doping
Basaloid Squamous Cell Carcinoma in Nasal Cavity
Basaloid squamous cell carcinoma (BSCC) is often founded in the head and neck region. However, BSCC in the sinonasal tract is rare. We report here on the case of a 58-yr-old woman who presented with nasal obstruction and epistaxis. Computed tomography and examination of the nasal cavity revealed a tumor mass that originated from the right inferior turbinate with erosion of the nasal floor. The tumor that was attached to the inferior turbinate, the lateral nasal wall and the eroded right side hard palate, and so all this was resected. Histopathologic examination of the excised tumor confirmed BSCC in the nasal cavity. We report here on a nasal cavity BSCC that was treated with partial maxillectomy only
Decreased Angiopoietin Expression in Underactive Bladder Induced by Long-term Bladder Outlet Obstruction
Purpose Ischemia of the bladder can occur if neovascular formation cannot keep pace with hypoxia induced by chronic bladder outlet obstruction (BOO). The aim of this study was to examine changes in angiogenesis growth factor expression generated by chronic BOO in a rat model of underactive bladder. Methods Twenty female Sprague-Dawley rats aged 6 weeks were assigned to 4 groups (5 rats per group). Group 1 was the control. Group 2 underwent sham surgery. The rats in groups 3 and 4 underwent BOO and were followed up for 1 week and 8 weeks. Cystometry was carried out together with bladder tissue analysis at 1 week and 8 weeks postoperatively. Real-time polymerase chain reaction (PCR) assays were conducted to determine the expression level of angiogenesis-related growth factors. A hypoxia signaling pathway PCR array was additionally carried out. Results The group that underwent BOO for 8 weeks showed abnormal bladder function, with a diminished intercontraction interval, decreased maximal voiding pressure, and higher volume of residual urine (P<0.05). Hypoxia-inducible factor-1 alpha expression was elevated in this group. The expression levels of vascular endothelial growth factor (VEGF) and VEGF receptor messenger RNA (mRNA) in the BOO group were comparable to those in the control group. However, angiotensin/tie receptor mRNA expression levels increased at 1 week after BOO, but decreased at 8 weeks after BOO. In animals that underwent BOO, fewer blood vessels exhibited positive immunofluorescent staining for von Willebrand factor. Alterations were also seen in the hypoxia signaling pathway PCR array. Conclusions In a rat model of underactive bladder caused by surgical BOO, reduced angiopoietin expression was demonstrated. This observation might underlie visceral ischemia and fibrosis associated with the procedure. The findings of this study might offer an improved understanding of the disease processes underlying BOO and facilitate selection of the appropriate time to repair the organ in this condition
LONG-TERM OUTCOMES OF INTRAVASCULAR ULTRASOUND GUIDANCE BARE METAL STENT VERSUS DRUG ELUTING STENT IMPLANTATION IN PATIENTS WITH ST-ELEVATION MYOCARDIAL INFARCTION UNDERGOING PRIMARY PERCUTANEOUS CORONARY INTERVENTION
Differential Gene Expression in the Penile Cavernosum of Streptozotocin-Induced Diabetic Rats
Purpose Men with diabetes mellitus (DM) often present with severe erectile dysfunction (ED). This ED is less responsive to current pharmacological therapies. If we know the upregulated or downregulated genes of diabetic ED, we can inhibit or enhance the expression of such genes through RNA or gene overexpression. Methods To investigate gene changes associated with ED in type 1 DM, we examined the alterations of gene expression in the cavernosum of streptozotocin-induced diabetic rats. Specifically, we considered 11,636 genes (9,623 upregulated and 2,013 downregulated) to be differentially expressed in the diabetic rat cavernosum group (n=4) compared to the control group (n=4). The analysis of differentially expressed genes using the gene ontology (GO) classification indicated that the following were enriched: downregulated genes such as cell cycle, extracellular matrix, glycosylphosphatidylinositol-anchor biosynthesis and upregulated genes such as calcium signaling, neurotrophin signaling, apoptosis, arginine and proline metabolism, gap junction, transforming growth factor-β signaling, tight junction, vascular smooth muscle contraction, and vascular endothelial growth factor (VEGF) signaling. We examined a more than 2-fold upregulated or downregulated change in expression, using real time polymerase chain reaction. Analysis of differentially expressed genes, using the GO classification, indicated the enrichment Results Of the 41,105 genes initially considered, statistical filtering of the array analysis showed 9,623 upregulated genes and 2,013 downregulated genes with at least 2-fold changes in expression (P<0.05). With Bonferroni correction, SLC2A9 (solute carrier family 2 member 9), LRRC20 (leucine rick repeat containing 20), PLK1 (polo like kinase 1), and AATK (apoptosis-associated tyrosine kinase) were all 2-fold changed genes. Conclusions This study broadens the scope of candidate genes that may be relevant to the pathophysiology of diabetic ED. In particular, their enhancement or inhibition could represent a novel treatment for diabetic ED
A complication of subclavian venous catheterization: extravascular kinking, knotting, and entrapment of the guidewire -A case report-
Various complications of central venous catheterization have been reported, some of which are well-known, while others are described as a sporadic events. We experienced a case of left subclavian venous catheterization complicated by extravascular knotting, kinking, and entrapment of the guidewire and the guidewire was removed surgically. Although minimal resistance was encountered during guidewire insertion, the guidewire was advanced approximately 30 cm. Physicians should be aware of these rare potential complications when a guidewire is advanced if any resistance is encountered
Clinical Outcomes of Silk Patch in Acute Tympanic Membrane Perforation
ObjectivesThe silk patch is a thin transparent patch that is produced from silk fibroin. In this study, we investigated the treatment effects of the silk patch in patients with traumatic tympanic membrane perforation (TTMP).MethodsThe closure rate, otorrhea rate, and closure time in all patients and the closure time in successful patients were compared between the paper patch and silk patch groups.ResultsDemographic data (gender, site, age, traumatic duration, preoperative air-bone gap, and perforation size and location) were not significantly different between the two groups. The closure rate and otorrhea rate were not significantly different between the two groups. However, the closure time was different between the two groups (closure time of all patients, P=0.031; closure time of successful patients, P=0.037).ConclusionThe silk patch which has transparent, elastic, adhesive, and hyper-keratinizing properties results in a more efficient closure time than the paper patch in the treatment of TTMP patients. We therefore believe that the silk patch should be recommended for the treatment of acute tympanic membrane perforation
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